Description PLASMA DISPLAY PANEL

Technical Field

[I] This document relates to a plasma display panel Background Art

[2] A plasma display panel includes phosphor layers inside discharge eels partitioned by barrier ribs and a plurality of electrodes. Driving signals are supplied to the discharge eels through the electrodes. [3] When the driving signal generates a discharge inside the discharge eels, a discharge gas filed in the discharge eels generates vacuum ultraviolet rays, which thereby cause phosphors formed inside the discharge eels to emit light, thus displaying an image on the screen of the plasma display panel

Disclosure of Invention

Brief Description of the Drawings [4] FIGs. 1 to 4 illustrate an example of a structure of a plasma display panel according to an exemplary embodiment; [5] FIG. 5 illustrates a reason why at least one of a first electrode or a second electrode has a single-layered structure; [6] FIG. 6 illustrates an example of a structure in which a black layer is added between first and second electrodes and a front substrate; [7] FIGs. 7 to 11 illustrate a first implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment; [8] FIG. 12 illustrates a second implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment; [9] FIGs. 13 and 14 illustrate a third implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment; [10] FIGs. 15 and 16 illustrate a fourth implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment;

[I I] FIG. 17 illustrates a fifth implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment;

[12] FIGs. 18 to 20 are diagrams for explaining an interval between line portions and an interval between connecting portions; [13] FIG. 21 illustrates a frame for achieving a gray scale of an image in the plasma display panel according to the exemplary embodiment; and

[14] FIG. 22 illustrates an example of an operation of the plasma display panel according to the exemplary embodiment. Mode for the Invention

[15] FIGs. 1 to 4 illustrate an example of a structure of a plasma display panel according to an exemplary embodiment.

[16] As illustrated in FIG. 1, the plasma display panel according to one embodiment includes a front substrate 101 and a rear substrate 111 which coalesce each other. On the front substrate 101, a first electrode 102 and a second electrode 103 are positioned in parallel to each other. On the rear substrate 111, a third electrode 113 is positioned to intersect the first electrode 102 and the second electrode 103.

[17] At least one of the first electrode 102 or the second electrode 103 has a single- layered structure. For instance, at least one of the first electrode 102 or the second electrode 103 may be a bus electrode or ITO (indium-tin-oxide)-less electrode in which a transparent electrode is omitted.

[18] At least one of the first electrode 102 or the second electrode 103 includes an opaque metal with excellent electrical conductivity. Examples of the opaque metal with excellent electrical conductivity include silver (Ag), copper (Cu), and aluminum (Al) that are cheaper than ITO.

[19] The first electrode 102 and the second electrode 103 generate a discharge inside discharge spaces (i.e., discharge eels) and maintain the discharge of the discharge eels.

[20] An upper dielectric layer 104 for covering the first electrode 102 and the second electrode 103 is positioned on the front substrate 101 on which the first electrode 102 and the second electrode 103 are positioned. The upper dielectric layer 104 limits discharge currents of the first electrode 102 and the second electrode 103 and provides insulation between the first electrode 102 and the second electrode 103.

[21] A protective layer 105 is positioned on the upper dielectric layer 104 to facilitate discharge conditions. The protective layer 105 may be formed by deposition a material such as magnesium oxide (MgO) on the upper dielectric layer 104.

[22] A lower dielectric layer 115 for covering the third electrode 113 is positioned on the rear substrate 111 on which the third electrode 113 is positioned. The lower dielectric layer 115 provides insulation of the third electrode 113.

[23] Barrier ribs 112 of a stripe type, a wel type, a delta type, a honeycomb type, and the like, are positioned on the lower dielectric layer 115 to partition discharge spaces (i.e., discharge eels). A red (R) discharge eel, a green (G) discharge eel and a blue (B)

discharge eel, and the like, are positioned between the front substrate 101 and the rear substrate 111.

[24] In addition to the red (R), green (G), and blue (B) discharge eels, a white discharge eel or a yelow discharge eel may be further positioned between the front substrate 101 and the rear substrate 111.

[25] The widths of the red (R), green (G), and blue (B) discharge eels may be substantially equal to one another. Further, the width of at least one of the red (R), green (G), or blue (B) discharge eels may be different from the widths of the other discharge eels.

[26] For instance, as illustrated in FIG. 2, a width (a) of the red (R) discharge eel is the smallest, and widths (b and c) of the green (G) and blue (B) discharge eels are more than the width (a) of the red (R) discharge eel The width (b) of the green (G) discharge eel may be substantially equal to or different from the width (c) of the blue (B) discharge eel

[27] The widths of the above-described discharge eels determine the width of a phosphor layer 114 formed inside the discharge eels, which wil be described later. For instance, in a case of FIG. 2, the width of a blue (B) phosphor layer formed inside the blue (B) discharge eel is more than the width of a red (R) phosphor layer formed inside the red (R) discharge eel Further, the width of a green (G) phosphor layer formed inside the green (G) discharge eel is more than the width of a red (R) phosphor layer formed inside the red (R) discharge eel Hence, a color temperature of an image displayed on the plasma display panel can be improved.

[28] The plasma display panel according one embodiment may have various forms of barrier rib structures as wel as a structure of the barrier rib 112 illustrated in FIG. 1. For instance, the barrier rib 112 may include a first barrier rib 112b and a second barrier rib 112a. The barrier rib 112 may have a differential type barrier rib structure in which the height of the first barrier rib 112b and the height of the second barrier rib 112a are different from each other, a channel type barrier rib structure in which a channel usable as an exhaust path is formed on at least one of the first barrier rib 112b or the second barrier rib 112a, a hollow type barrier rib structure in which a hollow is formed on at least one of the first barrier rib 112b or the second barrier rib 112a, and the like.

[29] In the differential type barrier rib structure, as illustrated in FIG. 3, a height hi of the first barrier rib 112b is less than a height h2 of the second barrier rib 112a. Further, in the channel type barrier rib structure or the hollow type barrier rib structure, a channel

or a holow may be formed on the first barrier rib 112b.

[30] While the plasma display panel according to one embodiment has been illustrated and described to have the red (R), green (G), and blue (B) discharge eels arranged on the same line, it is possible to arrange them in a different pattern. For instance, a delta type arrangement in which the red (R), green (G), and blue (B) discharge eels are arranged in a triangle shape may be applicable. Further, the discharge eels may have a variety of polygonal shapes such as pentagonal and hexagonal shapes as wel as a rectangular shape.

[31] While FIG. 1 has illustrated and described a case where the barrier rib 112 is formed on the rear substrate 111, the barrier rib 112 may be formed on at least one of the front substrate 101 or the rear substrate 111.

[32] Each of the discharge eels partitioned by the barrier ribs 112 is filled with a predetermined discharge gas.

[33] The phosphor layers 114 for emitting visible light for an image display during the generation of an address discharge are positioned inside the discharge eels partitioned by the barrier ribs 112. For instance, red (R), green (G) and blue (B) phosphor layers may be positioned inside the discharge eels.

[34] A white phosphor layer and/or a yellow phosphor layer may be further positioned in addition to the red (R), green (G) and blue (B) phosphor layers.

[35] A thickness of at least one of the phosphor layers 114 formed inside the red (R), green (G) and blue (B) discharge eels may be different from thicknesses of the other phosphor layers. For instance, as illustrated in FIG. 4, thicknesses t2 and t3 of phosphor layers 114b and 114a inside the green (G) and blue (B) discharge eels are larger than a thickness tl of a phosphor layer 114c inside the red (R) discharge eel The thickness t2 of the phosphor layer 114b inside the green (G) discharge eel may be substantially equal to or different from the thickness t3 of the phosphor layer 114a inside the blue (B) discharge eel

[36] In FIG. 1, the upper dielectric layer 104 and the lower dielectric layer 115 each have a single-layered structure. However, at least one of the upper dielectric layer 104 or the lower dielectric layer 115 may have a multi-layered structure.

[37] A black layer (hot shown) for absorbing external light may be further positioned on the barrier rib 112 to prevent the reflection of the external light caused by the barrier rib 112.

[38] Further, another black layer (hot shown) may be further positioned at a specific position of the front substrate 101 corresponding to the barrier rib 112.

[39] The third electrode 113 positioned on the rear substrate 11 may have a substantially constant width or thickness. Further, a width or thickness of the third electrode 113 inside the discharge eel may be different from a width or thickness of the third electrode 113 outside the discharge eel For instance, a width or thickness of the third electrode 113 inside the discharge eel may be larger than a width or thickness of the third electrode 113 outside the discharge eel

[40] FIG. 5 illustrates a reason why at least one of a first electrode or a second electrode has a single-layered structure.

[41] As illustrated in (a) of FIG. 5, unlike the exemplary embodiment, a first electrode

210 and a second electrode 220 each have a multi-layered structure on a front substrate 200.

[42] For instance, the first electrode 210 and the second electrode 220 each include transparent electrodes 210a and 220a and bus electrodes 210b and 220b.

[43] The transparent electrodes 210a and 220a may include a transparent material such as

ITO. The bus electrodes 210b and 220b may include a metal material such as silver (Ag).

[44] The transparent electrodes 210a and 220a are formed and then the bus electrodes

210b and 220b are formed to complete the first electrode 210 and the second electrode 220.

[45] As illustrated in (b) of FIG. 5, the first electrode 102 and the second electrode 103 according to the exemplary embodiment each have a single-layered structure. For instance, at least one of the first electrode 102 or the second electrode 103 may be an ITO-less electrode in which a transparent electrode is omitted.

[46] At least one of the first electrode 102 or the second electrode 103 may include a substantially opaque metal material with excellent electrical conductivity. Examples of the opaque metal with excellent electrical conductivity include silver (Ag), copper (Cu) and aluminum (Al) that are cheaper than ITO. At least one of the first electrode 102 or the second electrode 103 may further include a black material such as carbon (C), cobalt (Co) or ruthenium (Ru).

[47] A process for forming the transparent electrodes 210a and 220a and a process for forming the bus electrodes 210b and 220b are required in (a) of FIG. 5. However, because a process for forming the transparent electrode is omitted in (b) of FIG. 5, the manufacturing cost can be reduced.

[48] Further, because an expensive material such as ITO is not used in (b) of FIG. 5, the manufacturing cost can be further reduced.

[49] FIG. 6 illustrates an example of a structure in which a Hack layer is added between first and second electrodes and a front substrate.

[50] As illustrated in FIG. 6, black layers 300a and 300b are positioned between the front substrate 101 and at least one of the first or second electrode 102 or 103, thereby preventing discoloration of the front substrate 101. A degree of blackness of the black layers 300a and 300b is higher than a degree of blackness of at least one of the first or second electrode 102 or 103.

[51] For instance, when the front substrate 101 directly contacts the first or second electrode 102 or 103, a predetermined area of the front substrate 101 directly contacting the first or second electrode 102 or 103 may change into a yelow-based color. The change of color is called a migration phenomenon. The black layers 300a and 300b prevent the migration phenomenon by preventing the direct contact of the front substrate 101 with the first or second electrode 102 or 103.

[52] The black layers 300a and 300b may include a black material of a dark color, for example, ruthenium (Ru).

[53] Since the black layers 300a and 300b are positioned between the front substrate 101 and the second electrode 103 and between the front substrate 101 and the first electrode 102, respectively, the generation of reflection light can be prevented even if the first and second electrodes 102 and 103 are formed of a material with a high reflectivity.

[54] FIGs. 7 to 11 illustrate a first implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment.

[55] As illustrated in FIG. 7, at least one of a first electrode 430 or a second electrode 460 may include at least one line portion intersecting a third electrode 370 inside a discharge eel partitioned by a barrier rib 400. For instance, the first electrode 430 includes first and second line portions 410a and 410b, and the second electrode 460 includes first and second line portions 440a and 440b.

[56] The line portions 410a, 410b, 440a and 440b are spaced apart from one another with a predetermined distance therebetween. For instance, the first and second line portions 410a and 410b of the first electrode 430 are spaced apart from each other with a distance dl therebetween. The first and second line portions 440a and 440b of the second electrode 1460 are spaced apart from each other with a distance d2 therebetween. The distance dl may be equal to or different from the distance d2.

[57] The line portions 410a, 410b, 440a and 440b each have a predetermined width. For instance, the first and second line portions 410a and 410b of the first electrode 430

have widths Wa and Wb, respectively. The width Wa may be equal to or different from the width Wb.

[58] A shape of the first electrode 430 may be symmetrical or asymmetrical to a shape of the second electrode 460 inside the discharge eel For instance, while the first electrode 430 may include three line portions, the second electrode 460 may include two line portions.

[59] The number of line portions in the first and second electrodes 430 and 460 may vary.

For instance, the first electrode 430 or the second electrode 460 may include 4 or 5 line portions.

[60] At least one of the first electrode 430 or the second electrode 460 may include at least one projecting portion projecting from the line portion. For instance, the first electrode 430 includes two projecting portions 420a and 420b projecting from the line portion 410a, and the second electrode 460 includes two projecting portions 450a and 450b projecting from the line portion 440a.

[61] The projecting portions 420a, 420b, 450a and 450b may project in a direction toward the center of the discharge eel inside the discharge eel

[62] The projecting portions 420a and 420b of the first electrode 430 may be positioned to face the projecting portions 450a and 450b of the second electrode 460. Hence, an interval gl between the projecting portions 420a and 420b and the projecting portions 450a and 450b may be smaller than an interval g2 between the first line portion 410a of the first electrode 430 and the first line portion 440a of the second electrode 460.

[63] When a driving signal is supplied to the first electrode 430 and the second electrode

460, a discharge firstly occurs between the projecting portions 420a and 420b of the first electrode 430 and the projecting portions 450a and 450b of the second electrode 460. Then, the discharge is diffused into the first and second line portions 410a and 410b of the first electrode 430 and the first and second line portions 440a and 440b of the second electrode 460.

[64] At least one of the fist electrode 430 or the second electrode 460 includes at least one connecting portion connecting the two or more line portions. For instance, connecting portions 420c and 42Od of the first electrode 430 connect the first and second line portions 410a and 410b to each other. Connecting portions 450c and 45Od of the second electrode 460 connect the first and second line portions 440a and 440b to each other. The connecting portions 420c, 42Od, 450c and 45Od allow a discharge generated between the projecting portions 420a, 420b, 450a and 450b to be easily diffused into the rear of the discharge eel partitioned by the barrier rib 400.

[65] At least one of the connecting portions 420c, 42Od, 450c and 45Od and at least one of the projecting portions 420a, 420b, 450a and 450b may overlap each other in a direction parallel to the third electrode 470. Preferably, at least one of the connecting portions 420c, 42Od, 450c and 45Od and at least one of the projecting portions 420a, 420b, 450a and 450b may be positioned in a straight line.

[66] For instance, the connecting portion 420c and the projecting portion 420a of the first electrode 430 overlap each other in a direction parallel to the third electrode 470, and the connecting portion 42Od and the projecting portion 420b of the first electrode 430 overlap each other in a direction parallel to the third electrode 470.

[67] As illustrated in FIG. 8, (a) illustrates a case where a projecting portion and a connecting portion are not positioned in a straight line. In FIG. 8, an area defined by the dotted line indicates a light generation area of a phosphor layer. The fact that the light generation area is relatively wide means that a discharge is widely diffused. On the contrary, the fact that the light generation area is relatively narrow means that a discharge is not widely diffused.

[68] In (a) of FIG. 8, because a relatively narrow charge moving path is formed between first and second line portions and the projecting portion and the connecting portion are not positioned in a straight line, it is difficult to smoothly diffuse a discharge generated between the projecting portion of the first electrode and the projecting portion of the second electrode into the second portions of the first and second electrodes. FJence, the driving efficiency can be relatively low.

[69] Similar to FIG. 7, (b) of FIG. 8 illustrates a case where a projecting portion and a connecting portion are positioned in a straight line. In this case, because a discharge generated between the projecting portion of the first electrode and the projecting portion of the second electrode is sufficiently diffused into the second portions of the first and second electrodes through the connecting portion overlapping the projecting portion, the driving efficiency can be improved.

[70] (c) of FIG. 8 illustrates another case where a projecting portion and a connecting portion are not positioned in a straight line. In (c) of FIG. 8, the number of connecting potions is more than the number of projecting portion so as to sufficiently widen a charge moving path between first and second line portions. It is likely to sufficiently diffuse a discharge generated between the projecting portion of the first electrode and the projecting portion of the second electrode into the second portions of the first and second electrodes. However, because an aperture ratio is reduced due to the connecting portion, a luminance and the driving efficiency can be reduced.

[71] Accordingly, it is preferable that the projecting portion and the connecting portion are positioned in a straight line.

[72] The number of projecting portions and the number of connecting portions of the first and second electrodes may be variously changed. For instance, as illustrated in FIG. 9, each of the first and second electrodes 430 and 460 may include one projecting portion and one connecting portion. In other words, the first electrode 430 includes one projecting portion 42Oe and one connecting portion 42Of, and the second electrode 460 includes one projecting portion 45Oe and one connecting portion 45Of.

[73] Further, a width of at least one of the plurality of line portions 410a, 410b, 440a and

440b may be different from widths of the other line portions. For instance, as illustrated in FIG. 10, a width Wa of the first line portion 410a of the first electrode 430 may be smaller than a width Wb of the second line portion 410b of the first electrode 430.

[74] Further, as illustrated in FIG. 11, a width Wa of the first line portion 410a may be larger than a width Wb of the second line portion 410b.

[75] FIG. 12 illustrates a second implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment. The description of structures and components identical or equivalent to those illustrated and described in FIGs. 7 to 11 is briefly made or is entirely omitted in FIG. 12.

[76] As illustrated in FIG. 12, a first electrode 430 includes projecting portions 520a and

520b and tail portions 52Oe and 52Of projecting from line portions 510a and 510b in a direction opposite a projecting direction of the projecting portions 520a and 520b. A second electrode 560 includes projecting portions 550a and 550b and tail portions 550e and 550f projecting from line portions 540a and 540b in a direction opposite a projecting direction of the projecting portions 550a and 550b.

[77] For instance, the projecting portions 520a, 520b, 550a and 550b may project from the first line portions 510a and 540a in a direction toward the center of a discharge eel partitioned by a barrier rib 500, and the tail portions 52Oe, 52Of, 550e and 550f may project from the second line portions 510b and 540b in a direction opposite the projecting direction of the projecting portions 520a, 520b, 550a and 550b.

[78] As above, because the first electrode 530 and the second electrode 560 each include the tail portions 52Oe, 52Of, 550e and 550f, a discharge generated between the projecting portions 520a, 520b, 550a and 550b can be more widely diffused inside the discharge eel FJence, a luminance and the driving efficiency can be improved.

[79] The tail portions 52Oe, 52Of, 550e and 550f may be positioned in a straight line with

the projecting portions 520a, 520b, 550a and 550b and connecting portions 520c, 52Od, 550c and 550d.

[80] For instance, in FIG. 12, the projecting portion includes the first projecting portions

520a and 550a and the second projecting portions 520b and 550b; the tail portion includes the first tail portions 52Oe and 550e and the second tail portions 52Of and 550f projecting in a direction opposite the projecting direction of the first projecting portions 520a and 550a and the second projecting portions 520b and 550b; and the connecting portion includes the first connecting portions 520c and 550c corresponding to the first projecting portions 520a and 550a and the first tail portions 52Oe and 550e and the second connecting portions 52Od and 550d corresponding to the second projecting portions 520b and 550b and the second tail portions 52Of and 550f. The first projecting portions 520a and 550a, the first connecting portions 520c and 550c, and the first tail portions 52Oe and 550e are positioned in a straight line, and the second projecting portions 520b and 550b, the second connecting portions 52Od and 550d, and the second tail portions 52Of and 550f are positioned in a straight line.

[81] In the panel structure of FIG. 12, a discharge generated between the projecting portions 520a, 520b, 550a and 550b can be more widely diffused inside the discharge eel along the connecting portions 520c, 52Od, 550c and 550d and the tail portions 52Oe, 52Of, 550e and 550f.

[82] FIGs. 13 and 14 illustrate a third implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment. The description of structures and components identical or equivalent to those illustrated and described in FIGs. 7 to 11 is briefly made or is entirely omitted in FIGs. 13 and 14.

[83] As illustrated in FIG. 13, a shape of projecting portions 620a, 620b, 650a and 650b may be different from a shape of tail portions 62Oe, 62Of, 65Oe and 65Of.

[84] For instance, a width of the projecting portions 620a, 620b, 650a and 650b may be set to a width WlO, and a width of the tail portions 62Oe, 62Of, 65Oe and 65Of may be set to a width W20 smaller than the width WlO.

[85] As above, when the width WlO of the projecting portions 620a, 620b, 650a and 650b is larger than the width W20 of the tail portions 62Oe, 62Of, 65Oe and 65Of, a firing voltage of a discharge generated between a first electrode 630 and a second electrode 660 can be lowered.

[86] As illustrated in FIG. 14, a width of the projecting portions 620a, 620b, 650a and

650b may be set to a width W20, and a width of the tail portions 62Oe, 62Of, 65Oe and 65Of may be set to a width WlO larger than the width W20.

[87] As above, when the width W20 of the projecting portions 620a, 620b, 650a and 650b is smaller than the width WlO of the tail portions 62Oe, 62Of, 65Oe and 65Of, a discharge generated inside the discharge eel can be more widely diffused into the rear of the discharge eel

[88] FIGs. 15 and 16 illustrate a fourth implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment. The description of structures and components identical or equivalent to those illustrated and described in FIGs. 7 to 11 is briefly made or is entirely omitted in FIGs. 15 and 16.

[89] As illustrated in FIG. 15, a length of projecting portions 720a, 720b, 750a and 750b may be different from a length of tail portions 72Oe, 72Of, 75Oe and 75Of.

[90] For instance, a length of the projecting portions 720a, 720b, 750a and 750b may be set to a length Ll, and a length of the tail portions 72Oe, 72Of, 75Oe and 75Of may be set to a length L2 shorter than the length Ll.

[91] As above, when the length Ll of the projecting portions 720a, 720b, 750a and 750b is longer than the length L2 of the tail portions 72Oe, 72Of, 75Oe and 75Of, a firing voltage of a discharge generated between a first electrode 730 and a second electrode 760 can be lowered.

[92] As illustrated in FIG. 16, a length of the projecting portions 720a, 720b, 750a and

750b may be set to a length L2, and a length of the tail portions 72Oe, 72Of, 75Oe and 75Of may be set to a length Ll longer than the length L2.

[93] As above, when the length L2 of the projecting portions 720a, 720b, 750a and 750b is shorter than the length Ll of the tail portions 72Oe, 72Of, 75Oe and 75Of, a discharge generated inside the discharge eel can be more efficiently diffused into the rear of the discharge eel

[94] Considering that light is mainly generated in an discharge diffusing area inside the discharge eel, the length Ll of the tail portions 72Oe, 72Of, 75Oe and 75Of may be longer than the length L2 of the projecting portions 720a, 720b, 750a and 750b so as to improve a luminance of an image.

[95] FIG. 17 illustrates a fifth implementation associated with first and second electrodes of the plasma display panel according to the exemplary embodiment. The description of structures and components identical or equivalent to those illustrated and described in FIGs. 7 to 11 is briefly made or is entirety omitted in FIG. 17.

[96] As illustrated in FIG. 17, projecting portions 820a, 820b, 850a and 850b may include a portion with the curvature. Tail portions 82Oe, 82Of, 850e and 850f may include a portion with the curvature.

[97] A portion where the projecting portions 820a, 820b, 850a and 850b are adjacent to line portions 810a, 810b, 840a and 840b may include the curvature. Further, a portion where the line portions 810a, 810b, 840a and 840b are adjacent to connecting portions 820c, 82Od, 850c and 1850c may include the curvature.

[98] In the panel structure of FIG. 17, a first electrode 830 and a second electrode 860 can be easily manufactured. Further, the portion with the curvature prevents wall charges from being excessively accumulated on a specific portion during a driving of the panel, and thus a driving stability can be improved.

[99] FIGs. 18 to 20 are diagrams for explaining an interval between line portions and an interval between connecting portions.

[100] FIGs. 18 and 20 illustrate a case where an interval g3 between two successively positioned line portions 910a and 910b or 940a and 940b among a plurality of line portions is shorter than an interval g4 between two successively positioned connecting portions 920c and 92Od or 950c and 95Od among a plurality of connecting portions.

[101] In FIG. 18, it seems to increase the interval g4 between the two successively positioned connecting portions 920c and 92Od or 950c and 95Od in a state where the interval g3 between the two successively positioned line portions 910a and 910b or 940a and 940b is maintained. In FIG. 19, it seems to reduce the interval g3 between the two successively positioned line portions 910a and 910b or 940a and 940b in a state where the interval g4 between the two successively positioned connecting portions 920c and 92Od or 950c and 95Od is maintained.

[102] In FIG. 18, a discharge generated between projecting portions 920a, 920b, 950a and 950b of first and second electrodes 930 and 960 can be widely diffused. However, because the interval g4 is excessively large, the discharge intensity can be excessively reduced in a middle portion of the discharge eel Hence, a luminance can be reduced.

[103] In FIG. 19, a sufficiently strong discharge can occur in the middle portion of the discharge eel. However, a discharge generated between the projecting portions 920a, 920b, 950a and 950b of the first and second electrodes 930 and 960 cannot be sufficiently diffused into the rear of the discharge eel Hence, a luminance can be reduced.

[104] On the contrary, in FIG. 20, an interval g3 between the two successively positioned line portions 910a and 910b or 940a and 940b is longer than an interval g4 between the two successively positioned connecting portions 920c and 92Od or 950c and 95Od. In the panel structure of FIG. 20, a sufficiently strong discharge can occur in the middle portion of the discharge eel, and a discharge generated between the projecting

portions 920a, 920b, 950a and 950b of the first and second electrodes 930 and 960 can be widely diffused into the rear of the discharge eel Hence, a luminance and the driving efficiency can be improved.

[105] FIG. 21 illustrates a frame for achieving a gray scale of an image in the plasma display panel according to the exemplary embodiment.

[106] FIG. 22 illustrates an example of an operation of the plasma display panel according to the exemplary embodiment.

[107] As illustrated in FIG. 21, a frame for achieving a gray scale of an image in the plasma display panel according to the exemplary embodiment is divided into several subfields each having a different number of emission times.

[108] Each subfield is subdivided into a reset period for initializing all the eels, an address period for selecting eels to be discharged, and a sustain period for representing gray level in accordance with the number of discharges.

[109] For instance, if an image with 256-level gray scale is to be displayed, a frame, as illustrated in FIG. 21, is divided into 8 subfields SFl to SF8. Each of the 8 subfields SFl to SF8 is subdivided into a reset period, an address period, and a sustain period.

[110] The number of sustain signals supplied during the sustain period determines gray level weight in each of the subfields. For instance, in such a method of setting gray level weight of a first subfield to 2 and gray level weight of a second subfield to 2 , the sustain period increases in a ratio of 2° (where, n = 0, 1, 2, 3, 4, 5, 6, 7) in each of the subfields. Since the sustain period varies from one subfield to the next subfield, a specific gray level is achieved by controlling the sustain period which are to be used for discharging each of the selected eels, i.e., the number of sustain discharges that are realized in each of the discharge eels.

[I l l] The plasma display panel according to the exemplary embodiment uses a plurality of frames to display an image for 1 second. For instance, 60 frames are used to display an image 1 second. In this case, a time width T of one frame may be 1/60 seconds, i.e., 16.67 ms.

[112] In FIG. 21, one frame includes 8 subfields. However, the number of subfields constituting one frame may vary. For instance, one frame may include 12 or 10 subfields.

[113] Further, in FIG. 21, the subfields are arranged in increasing order of gray level weight. However, he subfields may be arranged in decreasing order of gray level weight, or the subfields may be arranged regardless of gray level weight.

[114] FIG. 22 illustrates an example of an operation of the plasma display panel according to the exemplary embodiment in one subfield of a plurality of subfields of one frame

as illustrated in FIG. 21.

[115] During a pre -reset period prior to a reset period, a first signal with a gradually falling voltage is supplied to a first electrode Y. A second signal corresponding to the first signal is supplied to a second electrode Z. A polarity direction of the second signal is opposite to a polarity direction of the first signal. The second signal is constantly maintained at a voltage Vpz. The voltage Vpz may be substantially equal to a voltage (i.e., a sustain voltage Vs) of a sustain signal (SUS) to be supplied during a sustain period.

[116] As above, when the first signal is supplied to the first electrode Y and the second signal is supplied to the second electrode Z during the pre-reset period, wall charges of a predetermined polarity are accumulated on the first electrode Y, and wall charges of a polarity opposite the polarity of the wall charges accumulated on the first electrode Y are accumulated on the second electrode Z. For instance, wall charges of a positive polarity are accumulated on the first electrode Y, and wall charges of a negative polarity are accumulated on the second electrode Z.

[117] During a reset period, a third signal is supplied to the first electrode Y. The third signal includes a first rising signal and a second rising signal The first rising signal gradually rises from a second voltage V2 to a third voltage V3 with a first slope, and the second rising signal gradually rises from the third voltage V3 to a fourth voltage V4 with a second slope.

[118] The third signal generates a weak dark discharge (i.e., a setup discharge) inside the discharge eel during a setup period of the reset period, thereby accumulating a proper amount of wall charges inside the discharge eel

[119] The setup discharge does not occur at a voltage equal to or less than the third voltage V3, and the setup discharge can occur at a voltage equal to or more than the third voltage V3. Therefore, a voltage of the first electrode Y rapidly rises up to the third voltage V3 and then lowly rises. FJence, an excessive increase in a time width of the setup period can be prevented, and a stability of the setup discharge can be improved. Considering this, it is preferable that the second slope is gentler than the first slope.

[120] WaU charges accumulated inside the discharge eels during the pre-reset period can assist the setup discharge generated during the setup period. Accordingly, although a voltage of the third signal is lowered, the stable setup discharge can occur. When the voltage of the third signal is lowered, the intensity of the setup discharge can be reduced and a reduction in the contrast characteristic can be prevented.

[121] As explained in FIG. 5, a case where the first electrode and the second electrode each

have the single-layered structure has a lower aperture ratio than a case where the first electrode and the second electrode each have the multi-layered structure, and thus a contrast characteristic can be reduced.

[122] On the contrary, the operation during the pre-reset period prior to the reset period can prevent a reduction in the contrast characteristic even if the first electrode and the second electrode each have the single-layered structure.

[123] A subfield, which is first arranged in time order in a plurality of subfields of one frame, may include a pre-reset period prior to a reset period so as to obtain sufficient driving time. Or, two or three subfields may include a pre-reset period prior to a reset period.

[124] During a set-down period of the reset period, a fourth signal of a polarity direction opposite a polarity direction of the third signal is supplied to the first electrode Y. The fourth signal gradually falls from a fifth voltage V5 lower than a peak voltage (i.e., the fourth voltage V4) of the third signal to a sixth voltage V6. The fourth signal generates a weak erase discharge (i.e., a set-down discharge) inside the discharge eel Furthermore, the remaining wall charges are uniform inside the discharge eels to the extent that an address discharge can be stably performed.

[125] During an address period, a scan bias signal, which is maintained at a seventh voltage V7 higher than a lowest voltage (i.e., the sixth voltage V6) of the fourth signal, is supplied to the first electrode Y.

[126] A scan signal (Scan), which falls from the scan bias signal by a scan voltage magnitu de δVy, is supplied to the first electrode Y.

[127] The width of the scan signal may vary from one subfield to the next subfield. For instance, the width of a scan signal in a subfield may be larger than the width of a scan signal in the next subfield in time order. Further, the width of the scan signal may be gradually reduced in the order of 2.6μs , 2.3μs , 2. lμs , 1.9μs , etc., or in the order of 2.6μs, 2.3μs, 2.3μs, 2.1μs, 1.9μs, 1.9μs, etc.

[128] As above, when the scan signal (Scan) is supplied to the first electrode Y, a data signal (data) corresponding to the scan signal (Scan) is supplied to the third electrode X. The data signal (data) rises from a ground level voltage GND by a data voltage magnitude δVd.

[129] As the voltage difference between the scan signal (Scan) and the data signal (data) is added to the wall voltage generated during the reset period, an address discharge is generated within the discharge eel to which the data signal (data) is supplied.

[130] A sustain bias signal is supplied to the second electrode Z during the address period

to prevent the generation of the unstable address discharge by interference of the second electrode Z. The sustain bias signal is substantially maintained at a sustain bias voltage Vz which is lower than the sustain voltage Vs and higher than the ground level voltage GND.

[131] During the sustain period, a sustain signal (SUS) is alternately supplied to the first electrode Y and the second electrode Z. As the wal voltage within the discharge eel selected by performing the address discharge is added to the sustain voltage Vs of the sustain signal (SUS), every time the sustain signal (SUS) is supplied, a sustain discharge, i.e., a display discharge occurs between the first electrode Y and the second electrode Z. Accordingly, a predetermined image is displayed on the plasma display panel

[132] A plurality of sustain signals are supplied during a sustain period of at least one subfield, and a width of at least one of the plurality of sustain signals may be different from widths of the other sustain signals. For instance, a width of the first supplied sustain signal among the plurality of sustain signals may be larger than widths of the other sustain signals. Hence, a sustain discharge can more stably occur.

[133] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the foregoing embodiments is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations wil be apparent to those skilled in the art.